Later that year, Tomalak was part of an elaborate deception involving Alidar Jarok and a supposed Romulan military build-up on Nelvana III. He allowed Jarok's defection to the Federation, and when the Enterprise-D illegally entered the Neutral Zone to investigate Jarok's reports, Tomalak had a pair of warbirds waiting for them. Tomalak boasted how he intended to "dissect the Enterprise-D for every precious bit of information," and then to display its broken hull in the capital on Romulus to both inspire the Romulan armies and serve as a reminder to any other traitors of the state. The crewmembers were to become prisoners-of-war. However, Tomalak was forced to withdraw when the Enterprise-D revealed it had brought along Klingon reinforcements. (TNG: "The Defector")

Tomalak made his first chronological appearance in Vulcan's Heart as a centurion in 2329. At this time, he commandeered a ground car to transport Spock, Ruanek, and Charvanek to a scout ship to escape from the Romulan Neutral Zone.

His next chronological appearance was in the DC Comicsvolume 2 issue #17: "The Weapon", set in 2366 where he accosted the Enterprise while her crew was being possessed by strange energy beings.

In the IDW Publishing comic series Star Trek: The Next Generation - Intelligence Gathering set in late 2368, he attempted to kidnap Data in order to get assistance with closing an inter-dimensional rift. He finally succeeded on Rete Mire and they were able to close the rift due to the sacrifice of a Romulan Centurion. When Picard asked him why he had gone to such lengths rather than simply asking for assistance and Riker answered by saying "Romulans fear disgrace more than death." Tomalak pointed out that at least one of the Enterprise-D crew understood Romulans.

In the short story "Performance Appraisal" from the No Limits collection set in 2369, Tomalak encountered Kat Mueller in the USS Grissom near the Neutral Zone border.

In the novel The Badlands, Book Two set in 2371, Tomalak had been promoted to High Commander and assigned Centurion Seylok to proceed to the Badlands to capture an artificial quantum singularity. Tomalak had promoted the young man to make it seem like a low priority mission in order to misdirect the changelings.

In the backstory to Star Trek Online Tomalak became Fleet Commander after Shinzon's coup, and led a punitive blockade of Remus through 2381. He remained loyal to the Empire when Donatra led several ships and planets in rebellion, forming the Imperial Romulan State (β) in opposition to the Imperial government led by PraetorTal'aura. Donatra soundly defeated him when he attacked her ships at Xanitla in 2383, and he was further disgraced by the defection of his handpicked second-in-command, AdmiralTaris. Tal'aura removed him from command and forced him into retirement at his estate on Romulus. His fate following the supernova of 2387 is unknown.